Incidental detection on imaging in patients with a diagnosis of prostate cancer – lucky find or poisoned chalice?
Incidental detection on imaging in patients with a diagnosis of prostate cancer – lucky find or poisoned chalice?
Tan HW, Patel R, Hague AG, Staton CA, Bala SB
Incidental detection on imaging is a common problem. This problem is becoming more challenging with the ever-increasing amount of imaging that is being performed. Patients with cancer often undergo imaging, sometimes in several different modalities, to stage their disease and guide treatment. Incidental detection on imaging during cancer work up is a burden and has the potential to delay cancer treatment. To investigate whether incidental detection on imaging affects the time to treatment date of patients with prostate cancer.
Patients with a new diagnosis of cancer over a 5-year period (2015-2019) in Sheffield Teaching Hospitals were identified from the cancer database. From this dataset, prostate cancers were identified. Scans of each patient at the time of their cancer diagnosis were identified and the reports of those scans were examined. Incidental detection was recorded. Incidental findings were defined using Young’s definition.1
(under results) Table 1: Summary of the scans that were performed for patients with prostate cancer.
(under results) Table 2: Summary of the number incidental findings detected by scans
(under results) Table 3: Summary of the number of incidental findings by anatomical location
A total of 2310 patient were identified. 1903 scans were performed. The majority were MRI (47%) and bone scans (42%). 1460 scans had incidental detection, 54% of these were on bone scans. Of the incidental detections 837 of these were in MSK system, 141 were renal, 85 were abdominal wall and 80 in the colon. 1456 of the 1460 incidentalomas were benign. There were 4 new, unrelated malignancies identified. These included adenocarcinoma of the lung and bowel, and bladder and oesophageal cancer. After the incidental detection, there were 94 recommendations of additional imaging, 7 endoscopies, 1 biopsy and 20 referrals to other specialities for opinions. Median time from first MDT discussion to treatment was 12 days for all patients, 9 days for patients with incidental findings and 13 days for patients without incidental findings. There were numerous cases where incidental detection of benign pathology had increased time to treatment, including a benign lung nodule delaying treatment by 103 days; a bladder cyst by 51 days and a chest wall lipoma by 6 months.
(under results) Table 4: Summary of the main incidental findings by anatomical location
(under results) Table 5: Summary of additional investigations performed for suspicious findings
(under results) Table 6: Summary of time to treatment for patients with and without incidental findings.
Incidental detection on imaging of patients with a new cancer diagnosis is a significant problem. The nature of vast majority of incidental detection is benign but can cause delay to cancer treatment. Amongst these patients, there were 4 unrelated primary malignancies discovered namely, colon cancer, esophageal cancer, bladder and lung cancer. The median time between 1st MDT discussion and treatment date were 36, 18, 2 and 8 days respectively for these 4 patients. This study showed that patients with incidental findings on imaging actually had a statistically significant faster time to treatment than patients without incidental findings, by 4 days.
